Affiliation: School of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.

ABSTRACT

Objectives: To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose.

Design: Systematic review and meta-analysis.

Data sources: Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied.

Study selection: Randomised controlled trials assessing the use of acetazolamide at 250 mg, 500 mg, or 750 mg daily versus placebo in adults as a drug intervention for the prophylaxis of acute mountain sickness. Included studies were required to state the administered dose of acetazolamide and to randomise participants before ascent to either acetazolamide or placebo. Two reviewers independently carried out the selection process.

Data extraction: Two reviewers extracted data concerning study methods, pharmacological intervention with acetazolamide, method of assessment of acute mountain sickness, and event rates in both control and intervention groups, which were verified and analysed by the review team collaboratively.

Conclusions: Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness. Acetazolamide 250 mg daily is the lowest effective dose to prevent acute mountain sickness for which evidence is available.

Mentions:
The literature search yielded 3133 articles from Medline and Embase (fig 1). Hand searches of the bibliographies identified two additional studies.2021 After removing duplicates, 3048 studies were reviewed against the prespecified exclusion criteria of which 3005 were excluded on the basis of the titles and abstracts. Of 43 full text articles retrieved and reviewed 32 did not meet the predefined inclusion criteria and were excluded (see supplementary table). The two studies identified from a hand search of bibliographies were excluded because one was not a randomised controlled trial and the outcome criteria were not clearly reported,20 and the other did not clearly report the incidence of acute mountain sickness among the study participants.21 Eleven papers (with 12 intervention arms) were included for meta-analysis. Table 1 shows the characteristics of the included studies.

Mentions:
The literature search yielded 3133 articles from Medline and Embase (fig 1). Hand searches of the bibliographies identified two additional studies.2021 After removing duplicates, 3048 studies were reviewed against the prespecified exclusion criteria of which 3005 were excluded on the basis of the titles and abstracts. Of 43 full text articles retrieved and reviewed 32 did not meet the predefined inclusion criteria and were excluded (see supplementary table). The two studies identified from a hand search of bibliographies were excluded because one was not a randomised controlled trial and the outcome criteria were not clearly reported,20 and the other did not clearly report the incidence of acute mountain sickness among the study participants.21 Eleven papers (with 12 intervention arms) were included for meta-analysis. Table 1 shows the characteristics of the included studies.

Bottom Line:
No language restrictions were applied.Heterogeneity ranged from I(2)=0% (500 mg subgroup) to I(2)=44% (750 mg subgroup).Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness.

Affiliation:
School of Medicine, University of Southampton, Southampton General Hospital, Southampton, UK.

ABSTRACT

Objectives: To assess the efficacy of three different daily doses of acetazolamide in the prevention of acute mountain sickness and to determine the lowest effective dose.

Design: Systematic review and meta-analysis.

Data sources: Medline and Embase along with a hand search of selected bibliographies. No language restrictions were applied.

Study selection: Randomised controlled trials assessing the use of acetazolamide at 250 mg, 500 mg, or 750 mg daily versus placebo in adults as a drug intervention for the prophylaxis of acute mountain sickness. Included studies were required to state the administered dose of acetazolamide and to randomise participants before ascent to either acetazolamide or placebo. Two reviewers independently carried out the selection process.

Data extraction: Two reviewers extracted data concerning study methods, pharmacological intervention with acetazolamide, method of assessment of acute mountain sickness, and event rates in both control and intervention groups, which were verified and analysed by the review team collaboratively.

Conclusions: Acetazolamide in doses of 250 mg, 500 mg, and 750 mg daily are all more effective than placebo for preventing acute mountain sickness. Acetazolamide 250 mg daily is the lowest effective dose to prevent acute mountain sickness for which evidence is available.